Automatic transmission control valve body structure

ABSTRACT

Structure of control valve body of automatic transmission has valve body enclosures having channels on opposing surfaces thereof; a separate plate sandwiched between the valve body enclosures for defining oil passages on both sides of the separate plate; and an orifice provided at the separate plate. The oil passages on both sides of the separate plate, which are upstream and downstream side oil passages located on upstream and downstream sides of the separate plate, communicate with each other through the orifice. Depth h, in a part facing to the orifice, of the channel corresponding to the downstream side oil passage is set to be shallower than depth of the channel corresponding to the upstream side oil passage, and the depth h of the channel in the part facing to the orifice and a diameter d of the orifice are set so as to satisfy relationship of h≦3d.

TECHNICAL FIELD

The present invention relates to a structure of a control valve body ofan automatic transmission, and more particularly to a structure ofanti-vibration measures of a separate plate of the control valve body.

BACKGROUND ART

FIG. 6 is a drawing for explaining an outline of an oil passage in acontrol valve body of an automatic transmission for a vehicle in arelated art. FIG. 6( a) is a sectional view schematically showing theoil passage in the control valve body. FIG. 6( b) is a sectional viewtaken along an A-A line of FIG. 6( a). FIG. 6( c) is an enlarged view ofan area B in FIG. 6( a), for explaining vibration of a separate plate.FIG. 6( d) is an enlarged explanatory view of an orifice adjacent areaof the separate plate.

The control valve body of the vehicle automatic transmission has a basicstructure in which a separate plate 120 is sandwiched between valve bodyenclosures 100 and 110 which are coupled together. The valve bodyenclosures 100 and 110 have, on opposing surfaces thereof, channels 100a and 110 a. Openings of these channels 100 a and 110 a are closed withthe separate plate 120 sandwiched between the valve body enclosures 100and 110, thereby separating the channels 100 a and 110 a and definingoil passages 101 and 102 in which working fluid flows.

The control valve body is provided with a solenoid, a spool (both notshown), etc. besides the oil passage inside the control valve body. Thevehicle automatic transmission is configured so that the working fluidis supplied to a certain frictional engagement element by switching orchanging the oil passage that provides the working fluid by driving thesolenoid and the spool.

In the control valve body, there is a spot by which one side oil passage101 and the other side oil passage 102 sandwiching the separate plate120 communicate with each other through an orifice 121 that is providedat the separate plate 120. For instance, the working fluid in the oneside oil passage 101 is pushed out to the other side oil passage 102through the orifice 121 of this spot.

Here, the working fluid pushed out to the oil passage 102 through theorifice 121 moves along a center axis X of the orifice 121, and forms aflow F1 (see FIG. 6 (c)) of the working fluid which flows on an extendedline of the orifice 121 along the center axis X. Since there is adifference in a velocity of the flow between this working fluid flow F1and a flow F2 of the working fluid positioned outside the extended lineof the orifice 121, a vortex ring S caused by this flow velocitydifference appears in the working fluid.

As shown in FIG. 6( b), since the orifice 121 is a small circular holeviewed from above, the vortex ring S formed in the oil passage 102 isformed cylindrically so as to surround the center axis X of the orifice121. The vortex ring S formed in the oil passage 102 grows or developswhile moving along the center axis X in a direction moving away from theorifice 121. Then, finally, a plurality of the vortex rings Scontinuously appear with the center axis X being a coaxial axis in apenetration direction (in an axial direction of the center axis X) ofthe orifice 121.

Here, the vortex ring S is a vortex that is different from a so-calledKarman vortex. The vortex ring S is a vortex that is generated, causedby the orifice 121 of the separate plate 120, in the downstream side oilpassage 102, and is a vortex of a jet passing through the orifice 121 ofthe control valve body.

With respect to the vortex ring S continuously appearing in thepenetration direction of the orifice 121, a pressure of a segment Sdbetween contiguous vortex rings S and S becomes higher than that of acore Sc of the vortex ring S. Because of this, when the working fluid inthe oil passage 101 is pushed out to the oil passage 102 through theorifice 121, fluctuation in up-and-down directions in the pressureadjacent to the orifice 121 in the oil passage 102 repeatedly occurs dueto the vortex ring S continuously appearing.

Here, a section 120 a of the separate plate 120, which is adjacent tothe orifice 121, is not supported by being sandwiched between the valvebody enclosures 100 and 110, thus rigidity of the section 120 a in thepenetration direction of the orifice 121 (in a direction orthogonal tothe separate plate 120) is low. Therefore, when the pressure adjacent tothe orifice 121 in the oil passage 102 fluctuates in the up-and-downdirections, the section 120 a of the separate plate 120, which isadjacent to the orifice 121, vibrates in the penetration direction ofthe orifice 121 (see an arrow a in the drawing) due to this pressurefluctuation, then a noise resulting from this vibration might begenerated.

As suppressing measures of the noise resulting from the vibration of theseparate plate 120, as shown in FIG. 6( d), it is said that forming acone surface 122 at a downstream side opening edge of the orifice 121formed at the separate plate 120, for instance, by coining process iseffective. This technique has been disclosed, for instance, in a PatentDocument 1.

According to this structure, as shown in FIG. 6( d), by slowing down aflow F1′ of the working fluid by the cone surface 122 and reducing aflow velocity difference between the working fluid flow F1′ and theworking fluid flow F2, the vibration at the section 120 a of theseparate plate 120, which is adjacent to the orifice 121, is suppressed,then the noise resulting from this vibration is suppressed.

However, only a flow velocity suppressing effect by the cone surface 122is not adequate for the noise suppression. The vibration at the section120 a of the separate plate 120, which is adjacent to the orifice 121,and the generation of the noise resulting from this vibration are notadequately suppressed, and thus a further measurement is required.

CITATION LIST Patent Document

Patent Document 1: Japanese Patent Provisional Publication No. 63-101355

SUMMARY OF THE INVENTION

The present invention was made in view of the above problem. An objectof the present invention is to provide a structure that can adequatelysuppress the vibration at the section of the separate plate 120, whichis adjacent to the orifice formed at the separate plate 120, andsuppress the generation of the noise resulting from this vibration.

The present invention is, as described above, a structure of a controlvalve body of an automatic transmission, in which a separate plate issandwiched between valve body enclosures. Then, channels are formed onopposing surfaces, which face to the separate plate, of the valve bodyenclosures located on both sides of the separate plate, and oil passagesare defined by separating the channels by the separate plate, and oneside oil passage and the other side oil passage located on both sides ofthe separate plate communicate with each other through an orifice thatis provided at the separate plate. Further, in the valve body enclosurein which the channel that corresponds to a downstream side oil passageof the oil passages is formed, a depth, at least in a part facing to theorifice, of the channel is set to be shallower than a depth of thechannel that corresponds to an upstream side oil passage of the oilpassages, and the depth h of the channel in the part facing to theorifice and a diameter d of the orifice are set so as to satisfy arelationship of h≦3d.

According to the present invention, in the valve body enclosure in whichthe channel corresponding to the downstream side oil passage is formed,the depth h of the channel facing to the orifice is set to be shallowerthan a depth of the other channel, and also the depth his set, withrespect to the diameter d of the orifice, so as to satisfy therelationship of h≦3d. Thus, the fluctuation in the up-and-downdirections of the pressure adjacent to the orifice in the downstreamside oil passage, which is caused by the vortex ring, can be prevented.It is therefore possible to prevent the section of the separate plate,which is adjacent to the orifice, from vibrating and prevent the noiseresulting from this vibration from being generated.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a sectional view showing a first embodiment of a control valvebody structure according to the present invention.

FIG. 2 is an enlarged view of a main part of FIG. 1

FIG. 3 is a sectional view showing a second embodiment of the controlvalve body structure according to the present invention.

FIG. 4 is a sectional view showing a third embodiment of the controlvalve body structure according to the present invention.

FIG. 5 is a sectional view showing some modifications of the controlvalve body structure as a fourth embodiment of the present invention.

FIG. 6 is a sectional view for explaining an oil passage in the controlvalve body of an automatic transmission for a vehicle in a related art.

EMBODIMENTS FOR CARRYING OUT THE INVENTION

FIG. 1 shows a first embodiment of a control valve body structureaccording to the present invention. FIG. 1( a) is a sectional view ofthe control valve body structure. FIG. 1( b) is a sectional view takenalong an A-A line of FIG. 1( a). FIG. 1( c) is a sectional view takenalong a C-C line of FIG. 1( a). FIG. 1( d) is a sectional view takenalong a B-B line of FIG. 1( a). Further, FIG. 2( a) is an enlarged viewof an area D of FIG. 1( a). FIG. 2( b) is a drawing for explainingformation of a vortex ring.

A control valve body 1 of an automatic transmission for a vehicle has abasic structure in which a separate plate 30 is sandwiched between valvebody enclosures 10 and 20 which are coupled together. The valve bodyenclosures 10 and 20 have, on opposing surfaces thereof, channels 10 aand 20 a. Openings of these channels 10 a and 20 a are closed with theseparate plate 30 sandwiched between the valve body enclosures 10 and20, thereby separating the channels 10 a and 20 a and defining oilpassages 11 and 21 in which working fluid flows.

In the control valve body, there is a spot by which one side oil passage11 and the other side oil passage 21 sandwiching the separate plate 30communicate with each other through an orifice 31 that is provided atthe separate plate 30. For instance, the working fluid in the one sideoil passage 11 moves to the other side oil passage 21 through theorifice 31 of this spot.

As shown in FIG. 1( d), the orifice 31 is formed into a small circularhole viewed from above, and has a diameter d. The orifice 31 is formedby penetrating the separate plate 30 in a thickness direction (in acoupling direction of the valve body enclosures 10 and 20). The workingfluid coming from the oil passage 11 toward the oil passage 21 throughthe orifice 31 flows along a center axis X passing through a center ofthe orifice 31 in a penetration direction of the orifice 31 as shown byan arrow F1 in FIG. 2( a).

In the oil passage 21 located on a downstream side in a flow directionof the working fluid, a depth of the channel 20 a of the valve bodyenclosure 20 defining the oil passage 21 is different between in an areafacing to the orifice 31 and its adjacent area and in the other area. Adepth h of the area facing to the orifice 31 and its adjacent area isshallower than a depth H1 of the other area. With this structure, asshown in FIGS. 1( b) and 1(c), in the oil passage 21, a passagecross-sectional area D of the area facing to the orifice 31 and itsadjacent area is smaller than a passage cross-sectional area D1 of theother area.

In the present embodiment, a protruding section 22 that protrudes towardan opening side of the channel 20 a, namely toward the orifice 31, isformed in the channel 20 a of the valve body enclosure 20, then thedepth of the channel 20 a becomes shallower by this protruding section22. The protruding section 22 is formed integrally with the valve bodyenclosure 20. The protruding section 22 is provided directly below theorifice 31 and in a predetermined area ranging from a position directlybelow the orifice 31 to upstream and downstream sides in a longitudinaldirection (i.e. in right and left directions in FIG. 1( a)) of thechannel 20 a with a position of the orifice 31 being a reference. Anopposing surface 22 a of the protruding section 22, which faces to theseparate plate 30, has a flat surface that is parallel to the separateplate 30, and this opposing surface 22 a is orthogonal to thepenetration direction of the orifice 31. That is, the opposing surface22 a is parallel to the separate plate 30 on which the orifice 31 isformed, and an area of the opposing surface 22 a is wider than an areaof the orifice 31 having the diameter d.

As shown in FIG. 2, in the present embodiment, the depth h from theorifice 31 (a lower surface 30 b of the separate plate 30) to theopposing surface 22 a is set to be smaller (shallower) than a distance Lthat is required for a vortex ring S to be formed in the penetrationdirection of the orifice 31 (in an orthogonal direction to the separateplate 30). Regarding this distance L, simulation and an experimentalresult showed that the distance L is dependent on the diameter d of theorifice 31 and if the distance L exceeds a distance that is three timesthat of the diameter d of the orifice 31, the vortex ring S is formed.Thus, in the present embodiment, as shown in FIG. 1( a), a protrusionheight H2 of the protruding section 22 from a bottom of the channel 20 ais set so as to satisfy a relationship of h≦3d (=L).

In the oil passage 21 having the protruding section 22, the workingfluid flowing into the oil passage 21 through the orifice 31 and formingthe flow (the arrow F1 in FIG. 2) toward the penetration direction ofthe orifice 31 in the oil passage 21 hits against or strikes theprotruding section 22, and as shown by an arrow F2 in FIG. 2, the flowof the working fluid is bent or curved in a different direction from thepenetration direction of the orifice 31.

As described above, the vortex ring S appears if the working fluid flowsthe predetermined distance L(=3d) or more along the penetrationdirection of the orifice 31. Thus, by setting the depth h from theorifice 31 to the opposing surface 22 a in the above manner, the flow ofthe working fluid is disturbed before the vortex ring S is generated,the vortex ring can therefore be prevented from continuously appearingin the penetration direction of the orifice 31.

Further, as shown in FIG. 2, due to the fact that the working fluidpassing through the orifice 31 strikes the opposing surface 22 a, a highpressure area H whose pressure is higher than that of part where theprotruding section 22 is not provided is formed directly below theorifice 31. Since this high pressure area H is formed directly below theorifice 31 and in its vicinity, a pressure of an area R which isadjacent to the orifice 31 in the oil passage 21 becomes high.Consequently, in this condition, the flow of the working fluid thatnewly passes through the orifice 31 and forms the flow F1 toward thepenetration direction of the orifice 31 is impeded by the high pressureuntil the flow of the working fluid passes through the orifice 31 andreaches the high pressure area H, and its flow velocity decreases. Withthis working, since a flow velocity difference between the working fluidaround the orifice 31 and the working fluid passing through the orifice31 becomes small, an influence by the working fluid passing through theorifice 31 is lessened. Thus, even if a vortex flow (the vortex ring) isgenerated, it is generation of a weak or poor vortex. Hence, even if thevortex ring is formed in the oil passage 21, a size of the vortex formedin the oil passage 21 is small, which is caused by the fact that theflow velocity difference becomes small, as compared with a related artcase where the high pressure area H is not formed.

As a consequence, a difference between a pressure of a core of thevortex ring (see Sc in FIG. 6) and a pressure around the vortex ring(see Sd in FIG. 6) becomes small as compared with a case where thepressure of the adjacent area R is not high. With this working, even ifthe vortex ring continuously appears in the penetration direction of theorifice 31 in the oil passage 21, since a pressure on the lower surface30 b side of the separate plate 30 does not periodically widelyfluctuate in the up-and-down directions, it is possible to suppress thevibration of a section 30 a of the separate plate 30, which is adjacentto the orifice 31, and the generation of the noise caused by thevibration of the separate plate 30 can be suppressed.

As explained above, in the present embodiment, anti-vibration measuresof the separate plate 30 in the control valve body 1 of the automatictransmission are premised on the structure in which the control valvebody 1 is formed by sandwiching the separate plate 30 between the valvebody enclosures 10 and 20 which are coupled together. Then, the openingsof the channels 10 a and 20 a formed on the respective opposing surfacesof the valve body enclosures 10 and 20 are closed with the separateplate 30, and the oil passages 11 and 21 are formed on one side and theother side of the separate plate 30.

Further, one side oil passage 11 and the other side oil passage 21located on opposite sides of the separate plate 30 communicate with eachother through the orifice 31 provided at the separate plate 30. Inaddition, in the valve body enclosure 20 in which the channel 20 acorresponding to the downstream side oil passage 21 of one side and theother side oil passages 11 and 21 is formed, the protruding section 22protruding toward the opening side of the channel 20 a is provided inthe channel 20 a, then the depth h of the area facing to the orifice 31in the channel 20 a is set to be shallower than the depth H1 of theother area where the protruding section 22 is not provided.

With this structure, since the depth of the channel 20 a directly belowthe orifice 31 becomes shallower, the vortex ring is prevented fromcontinuously appearing in the penetration direction of the orifice 31 inthe downstream side oil passage 21. This can inhibit the pressure of thearea R adjacent to the orifice 31 of the separate plate 30 fromperiodically fluctuating in the up-and-down directions in the downstreamside oil passage 21, thereby preventing the generation of the noisecaused by the fact that the section 30 a of the separate plate 30, whichis adjacent to the orifice 31, vibrates.

Further, only by setting the depth of the channel 20 a of the valve bodyenclosure 20 to be shallow, the vibration of the section 30 a of theseparate plate 30, which is adjacent to the orifice 31, is suppressedand the noise resulting from the vibration can be suppressed. Therefore,there is no need for the control valve body to be machined more thannecessary. As a consequence, the vibration and the generation of thenoise resulting from the vibration can be suppressed without increasinga manufacturing cost.

In addition, the high pressure area H is formed directly below theorifice 31, and the flow velocity of the working fluid forming the flowF1 toward the penetration direction of the orifice 31 decreases, thenthe flow velocity difference between the working fluid forming the flowF1 and the working fluid flowing outside the area positioned directlybelow the orifice 31 becomes small. Thus, even if the vortex flow (thevortex ring) is generated in the oil passage 21, it is the generation ofthe weak or poor vortex, then the vortex ring formed in the oil passage21 becomes small.

As a result, since the difference between the pressure of the core ofthe vortex ring and the pressure around the vortex ring is small, evenif the vortex ring is continuously formed on the extended line of theorifice 31 in the oil passage 21, the pressure difference between thecore of the vortex ring and a segment between contiguous vortex ringsbecomes small, thereby inhibiting the pressure on the lower surface 30 bside of the separate plate 30 from periodically widely fluctuating inthe up-and-down directions. It is therefore possible to suppress thevibration of the section 30 a of the separate plate 30, which isadjacent to the orifice 31, and suppress the generation of the noiseresulting from the vibration of the separate plate 30.

Furthermore, the relationship between the depth h from the orifice 31 tothe opposing surface 22 a (a bottom of the oil passage) of theprotruding section 22 located directly below the orifice 31 and thediameter d of the orifice 31 is set so as to satisfy the relationship ofh≦3d (=L), then the depth h is set to be smaller than or equal to thedistance L that is required for a first vortex ring to be formed in thepenetration direction of the orifice 31.

With these structure and setting, the depth of the channel 20 a locateddirectly below the orifice 31 becomes shallower than a depth requiredfor the generation and the growth of the vortex ring, and flow of theworking fluid is disturbed before the first vortex ring is generateddirectly below the orifice 31. This thus prevents the vortex ring fromcontinuously appearing in the penetration direction of the orifice 31 inthe oil passage 21.

Here, even if the vortex ring S is formed, since the moving or flowingdirection of the working fluid passing through the orifice 31 is bent orcurved by the opposing surface 22 a of the protruding section 22, thevortex ring S does not grow and is not continuously formed in thepenetration direction of the orifice 31.

Moreover, since the high pressure area H is formed directly below theorifice 31, the flow velocity of the working fluid forming the flow F1toward the penetration direction of the orifice 31 decreases, then theflow velocity difference between the working fluid forming the flow F1and the working fluid flowing outside the area positioned directly belowthe orifice 31 becomes small. Thus, even if the vortex flow (the vortexring) is generated in the oil passage 21, it is the generation of theweak or poor vortex, then the vortex ring formed in the oil passage 21becomes small.

As a result, since the difference between the pressure of the core ofthe vortex ring and the pressure around the vortex ring is small, evenif the vortex ring is continuously formed on the extended line of theorifice 31 in the oil passage 21, the pressure difference between thecore of the vortex ring and the segment between contiguous vortex ringsbecomes small, thereby inhibiting the pressure on the lower surface 30 bside of the separate plate 30 from periodically widely fluctuating inthe up-and-down directions.

Next, as a second embodiment, the other example of the protrudingsection in the downstream side oil passage will be explained. FIG. 3 isa drawing for explaining the protruding section according to the secondembodiment. FIG. 3( a) is a sectional view of the control valve bodywhen cut along the longitudinal direction of the oil passage 21. FIG. 3(b) is a sectional view taken along an A-A line of FIG. 3( a). FIG. 3( c)is an enlarged view of an area B of FIG. 3( a).

A protruding section 25 of the present embodiment has a circulartruncated cone shape. The protruding section 25 is provided so that atop portion flat surface section 25 a having a small diameter facestoward the orifice 31 side on the center axis X passing through thecenter of the orifice 31 and extending in the penetration direction ofthe orifice 31.

The top portion flat surface section 25 a has a flat surface that isparallel to the separate plate 30, and is orthogonal to the moving orflowing direction (see an arrow F1 in the drawing) of the working fluidpassing through the orifice 31. In the Present embodiment, a depth hfrom the orifice 31 (the lower surface 30 b of the separate plate 30) tothe top portion flat surface section 25 a is set to be smaller(shallower) than the distance L that is required for the first vortexring to be formed in the penetration direction of the orifice 31. In thesame manner as the first embodiment explained above, a protrusion heightH2 of the protruding section 25 from a bottom of the channel 20 a is setso as to satisfy the relationship of h≦3d (=L). Here, as can be seenfrom FIG. 3, an area of the top portion flat surface section 25 a of theprotruding section 25 is smaller than an area of the orifice 31 havingthe diameter d.

An outer peripheral surface 25 b of the protruding section 25 isinclined at a predetermined angle θ with respect to the center axis X.The working fluid flowing into the oil passage 21 through the orifice 31is guided in a direction moving away from the center axis X by thisouter peripheral surface 25 b, then the working fluid flow is convertedto a flow of a direction which radially expands or spreads when viewedfrom the center axis X.

In the oil passage 21 having the protruding section. 25, the flow (seethe arrow F1 in FIG. 3( c)) of the working fluid flowing into the oilpassage 21 through the orifice 31 is interfered by the protrudingsection 25, and is bent or curved in a different direction from thepenetration direction of the orifice 31 (see an arrow F2).

Here, since the depth h from the orifice 31 (the lower surface 30 b ofthe separate plate 30) to the top portion flat surface section 25 a,which is the narrowest separation distance between the orifice 31 (thelower surface 30 b of the separate plate 30) and the protruding section25, is set to be smaller (shallower) than the distance L that isrequired for the first vortex ring to be formed in the penetrationdirection of the orifice 31 (i.e. h≦3d), the flow of the working fluidis disturbed before the vortex ring is generated. It is thereforepossible to prevent the vortex ring from continuously appearing in thepenetration direction of the orifice 31 and prevent the vortex ring fromgrowing.

Further, also in the case of the protruding section 25, since the highpressure area H is formed directly below the orifice 31, even if thevortex flow (the vortex ring) is generated in the oil passage 21, it isthe generation of the weak or poor vortex, then the vortex ring formedin the oil passage 21 becomes small. Therefore, since the differencebetween the pressure of the core of the vortex ring and the pressurearound the vortex ring is small, even if the vortex ring is continuouslyformed on the extended line of the orifice 31 in the oil passage 21, thepressure difference between the core of the vortex ring and the segmentbetween contiguous vortex rings becomes small, thereby inhibiting thepressure on the lower surface 30 b side of the separate plate 30 fromperiodically widely fluctuating in the up-and-down directions.

As explained above, the second embodiment has the structure in which thecircular truncated cone-shaped protruding section 25 is formed in theposition directly below the orifice 31 in the channel 20 a with the topportion flat surface section 25 a facing toward the orifice 31 side, andthe depth h from the orifice 31 (the lower surface 30 b of the separateplate 30) to the top portion flat surface section 25 a is set to besmaller (shallower) than a depth H1 of the other area where theprotruding section 25 is not provided.

Also with this structure, since the vortex ring is prevented fromcontinuously appearing in the penetration direction of the orifice 31and the pressure of the area R adjacent to the orifice 31 of theseparate plate 30 is inhibited from periodically fluctuating in theup-and-down directions in the downstream side oil passage 21, thegeneration of the noise caused by the fact that the section 30 a of theseparate plate 30, which is adjacent to the orifice 31, vibrates can beprevented.

Here, although the present embodiment shows, as an example, the circulartruncated cone-shaped protruding section 25, a conical shape or acylindrical shape could be possible. Further, polygonal pyramid shape,polygonal truncated pyramid shape and polygonal prism shape such asquadrangular pyramid, truncated square pyramid and quadrangular prismcould be possible. Also in this case, the same effect can be obtained.

Next, as a third embodiment, the other example of the protruding sectionin the downstream side oil passage will be explained. FIG. 4 is adrawing for explaining the protruding section according to the thirdembodiment. FIG. 4( a) is a sectional view of the control valve bodywhen cut along the longitudinal direction of the oil passage 21. FIG. 4(b) is a sectional view taken along an A-A line of FIG. 4( a). FIG. 4( c)is an enlarged view of an area B of FIG. 4( a).

A protruding section 26 of this third embodiment is formed integrallywith the valve body enclosure 20. The protruding section 26 is provideddirectly below the orifice 31 and in a predetermined area ranging from aposition directly below the orifice 31 to upstream and downstream sidesin a longitudinal direction (i.e. in right and left directions in FIG.4( a)) of the channel 20 a.

An opposing surface 26 a of the protruding section 26, which faces tothe separate plate 30, is not parallel to the separate plate 30, and hasa flat inclined surface that is inclined at a predetermined angle 61. Aseparation distance from the lower surface 30 b of the separate plate 30on the oil passage 21 side to the opposing surface 26 a of theprotruding section 26 is greater, as a position on the opposing surface26 a gets closer to the downstream side of the oil passage 21. Further,a minimum depth h from the orifice 31 to the opposing surface 26 a in apart directly below the orifice 31 is set to be smaller (shallower) thanthe distance L that is required for the first vortex ring to be formedin the penetration direction of the orifice 31. In the same manner asthe first embodiment explained above, the angle θ1 of the opposingsurface 26 a is set so as to satisfy the relationship of h≦3d (=L).Here, as can be seen from FIG. 4, an area of the opposing surface 26 ais greater than the area of the orifice 31 having the diameter d.

In the oil passage 21 having the protruding section 26, a flow directionof the working fluid flowing into the oil passage 21 through the orifice31 and forming the flow (an arrow F1 in FIG. 4) toward the penetrationdirection of the orifice 31 in the oil passage 21 is bent or curved to adownward direction of the oil passage 21 by the opposing surface 26 a ofthe protruding section 26 (see an arrow F2). Here, in an upstream side Udirectly below the orifice 31 in the oil passage 21, since the minimumdepth h from the orifice 31 to the opposing surface 26 a is set to besmaller (shallower) than the distance L that is required for the firstvortex ring to be formed in the penetration direction of the orifice 31(i.e. h≦3d), the flow of the working fluid is disturbed before thevortex ring is generated. It is therefore possible to prevent the vortexring from continuously appearing in the penetration direction of theorifice 31 and prevent the vortex ring from growing.

Further, as can be seen from FIG. 4( c), in a downstream side D directlybelow the orifice 31 in the oil passage 21, a minimum depth h′ from theorifice 31 to the opposing surface 26 a is greater (deeper) than theminimum depth h in the upstream side U, and the vortex ring is formedmore easily than the upstream side U. However, since the opposingsurface 26 a is inclined so that the flow F2 of the working fluid whosemoving or flowing direction is changed at the opposing surface 26 a inthe upstream side U crosses the downstream side D, the generation of thevortex ring in the downstream side D is inhibited by this working fluidflow F2.

Furthermore, since the working fluid passing through the orifice 31 hitsagainst or strikes the opposing surface 26 a and its moving direction ischanged, in the same manner as the embodiments explained above, the highpressure area H is momentarily formed directly below the orifice 31.

Then, in this condition, the flow of the working fluid that newly passesthrough the orifice 31 and forms the flow F1 toward the penetrationdirection of the orifice 31 is impeded by the high pressure until theflow of the working fluid passes through the orifice 31 and reaches thehigh pressure area H, and its flow velocity decreases. With thisworking, since the flow velocity difference between the working fluidaround the orifice 31 and the working fluid passing through the orifice31 becomes small, the influence by the working fluid passing through theorifice 31 is lessened. Thus, even if the vortex flow is generated, itis generation of the weak or poor vortex.

Consequently, even if the vortex ring is continuously formed on theextended line of the orifice 31 in the oil passage 21, since thepressure difference between the core of the vortex ring and the segmentbetween contiguous vortex rings becomes small as compared with the casewhere the high pressure area H is not formed, the pressure on the lowersurface 30 b side of the separate plate 30 is inhibited fromperiodically widely fluctuating in the up-and-down directions. It istherefore possible to suppress the vibration of the section 30 a of theseparate plate 30, which is adjacent to the orifice 31, and suppress thegeneration of the noise resulting from the vibration of the separateplate 30.

As explained above, the protruding section 26 having the opposingsurface 26 a that is inclined with respect to the separate plate 30 isformed directly below the orifice 31 and in its vicinity in the channel20 a, and the depth h from the orifice 31 (the lower surface 30 b of theseparate plate 30) to the opposing surface 26 a is greater, as theposition on the opposing surface 26 a gets closer to the downstream sideof the oil passage 21. Further, the relationship between the minimumdepth h from the orifice 31 to the opposing surface 26 a in the partdirectly below the orifice 31 and the diameter d of the orifice 31 isset so as to satisfy the relationship of h≦3d (=L), then the depth h isset to be smaller than or equal to the distance L that is required forthe first vortex ring to be formed in the penetration direction of theorifice 31.

Also with this structure, since the vortex ring is prevented from beingcontinuously formed in the penetration direction of the orifice 31 andthe pressure of the area R adjacent to the orifice 31 of the separateplate 30 is inhibited from periodically fluctuating in the up-and-downdirections in the downstream side oil passage 21, the generation of thenoise caused by the fact that the section 30 a of the separate plate 30,which is adjacent to the orifice 31, vibrates can be prevented.

Here, in each of the embodiments described above, as the example, thecase where the shape of the orifice 31 is such circular shape that adistance from the center axis X is the same is explained. Meanwhile,simulation and an experimental result about the vortex ring formed inthe downstream side oil passage showed that the shape of the orifice 31also has an influence on the formation of the vortex ring, and if a flowof the working fluid that is faster than that around the orifice 31 isformed a predetermined distance X or more along the penetrationdirection (a center axis X direction) of the orifice 31 directly belowthe orifice 31 by the working fluid passing through the orifice 31, thevortex ring is continuously generated.

Thus, as modifications of the above-mentioned orifice shape, shapes ofthe orifice which can suppress the generation of the vortex ring will beexplained here.

FIG. 5 is a drawing for explaining the shape of the orifice and a speed(the velocity) of the working fluid in the downstream side oil passage.FIG. 5( a) is a drawing for explaining an orifice 35 having asubstantially cruciform shape. FIG. 5( c) is a drawing for explaining anorifice 36 having an almost star shape. FIG. 5( e) is a drawing forexplaining an orifice 37 having the other shape. FIGS. 5( b), 5(d) and5(f) are drawings that show the speed (the velocity) of the flow of theworking fluid formed in the downstream side oil passage by sizes ofarrows. As can be appreciated from FIG. 5, it can be understood thateach of the orifices 35, 36 and 37 shown in FIGS. 5( a), 5(c) and 5(e)is comprehensively an orifice whose plane shape is noncircular and has asubstantially inner tooth shape.

The orifice 35 shown in FIG. 5( a) has such shape that two long holeswhose both ends have an R-shape are arranged with a phase of one of thetwo long holes shifted by 90 degrees on the center axis X, which is thesubstantially cruciform shape viewed from above.

In a case of the orifice 35 having this shape, a velocity difference,which results from the passage cross-sectional area, between the workingfluid passing through a middle area D1 where the two long holes crossand the working fluid passing through a peripheral area D2 that enclosesthe middle area D1 arises. A flow velocity of a flow Fa of the workingfluid passing through the middle area D1 is higher than that of a flowFb of the working fluid passing through the peripheral area D2.

Here, the generation and the growth of the vortex ring become noticeablewhen the velocity difference between the working fluid flowing directlybelow the orifice 35 and the working fluid flowing outside the areapositioned directly below the orifice 35 is great. In the case of theorifice 35, when looking at the flow of the working fluid in crosssection of the line L1 (in cross section of the line L1, passing alongthe center axis X), the flow velocities Fa and Fb of the working fluidare lower from a middle of the orifice 35 toward a vicinity of theorifice 35. Then, a difference from a flow velocity Fc of the workingfluid flowing outside the area positioned directly below the orifice 35becomes small (Fa>Fb>Fc). Therefore, the generation and the growth ofthe vortex ring in the oil passage 21 located on the downstream side ofthe orifice 35 can be suppressed as compared with the orifice 31 of theabove embodiments.

Further, in a cross section of a line L2 (in a cross section of the lineL2, passing along the center axis X), since the peripheral area D2 isnot present, the flow velocity difference between the flow Fa of theworking fluid flowing directly below the orifice 35 and the flow Fc ofthe working fluid flowing outside the area positioned directly below theorifice 35 is still large. Meanwhile, regarding the flow velocitydifference between the flow of the working fluid flowing at the partpositioned directly below the orifice 35 and the flow Fc of the workingfluid flowing outside the area positioned directly below the orifice 35,a large flow velocity difference part (the cross section of the line L1)and a small flow velocity difference part (the cross section of the lineL2) are alternately positioned on the center axis X of the orifice 35.Then, the flow velocity difference becomes small as compared with theabove embodiments. Thus, the generation and the growth of the vortexring can be suppressed as compared with the orifice 31 of the aboveembodiments.

In addition, by setting the flow velocity difference so that the flowvelocity difference between the flow of the working fluid flowingdirectly below the orifice 35 and the flow of the working fluid flowingoutside the area positioned directly below the orifice 35 is differentaccording to an angle position on the center axis X of the orifice 35,an annular vortex ring whose core is positioned at the center axis X isnot easily formed in the downstream side of the oil passage 21. Here,even if the vortex ring appears, since the vortex ring is not circular,the shape of the vortex ring changes due to an inductive speed of thevortex, and its secondary generation is lost or extinguished. Thus, achange or fluctuation of a force acting on the separate plate 30 islessened. Also with these workings, since the pressure of the area Radjacent to the orifice 35 of the separate plate 30 can be inhibitedfrom periodically fluctuating in the up-and-down directions, thegeneration of the noise caused by the fact that the section 30 a of theseparate plate 30, which is adjacent to the orifice 35, vibrates can beprevented.

As explained above, by employing the substantially cruciform-shapedorifice 35 having such shape that the two long holes whose both endshave the R-shape are arranged with the phase of one of the two longholes shifted by 90 degrees on the center axis X, the generation and thegrowth of the vortex ring in the downstream side oil passage 21 can besuppressed. Then, the pressure of the area R adjacent to the orifice 35of the separate plate 30 can be inhibited from periodically fluctuatingin the up-and-down directions, and the generation of the noise caused bythe fact that the section 30 a of the separate plate 30, which isadjacent to the orifice 35, vibrates can be prevented.

The orifice 36 shown in FIG. 5( c) has the almost star shape viewed fromabove. Also in the case of the orifice 36 having this shape, a velocitydifference, which results from the passage cross-sectional area, betweenthe working fluid passing through a middle area D1 and the working fluidpassing through a peripheral area D2 that encloses the middle area D1arises. Then, as shown in FIG. 5( d), in a part where the peripheralarea D2 is provided in an area positioned directly below the orifice 36,a difference from a flow velocity Fc of the working fluid flowingoutside the area positioned directly below the orifice 36 becomes small(Fa>Fb>Fc). Therefore, the generation and the growth of the vortex ringin the oil passage 21 located on the downstream side of the orifice 36can be suppressed as compared with the orifice 31 of the aboveembodiments.

As explained above, also by employing the orifice 36 having the starshape viewed from a direction orthogonal to the separate plate 30 and byforming an opening of the orifice 36 by the middle area D1 located on acenter axis X of the orifice 36 and the peripheral area D2 locatedaround the middle area D1 with the peripheral area D2 arranged at apredetermined interval in a circumferential direction of the center axisX, the generation and the growth of the vortex ring in the downstreamside oil passage 21 can be suppressed.

In the case of the orifice 37 shown in FIG. 5( e), a plurality ofperipheral areas D2 are formed so that the peripheral areas D2 extendfrom a circumference of a middle area D1 formed by an imaginary circleIm1 in a direction moving away from the imaginary circle Im1. Eachperipheral area D2 has a different passage cross-sectional area, and isarranged at random on a center axis X of the orifice 37.

Therefore, different flow speeds (different flow velocities) (flows Fb,Fb′) exist around a middle area (a flow Fa) whose flow speed (flowvelocity) is highest, and an area whose flow velocity is lower than theflow Fa and is higher than the flow Fc of the working fluid flowingoutside the area positioned directly below the orifice 37 is formed atrandom. Also in the case of the orifice 37 having the shape shown inFIG. 5( e), the generation and the growth of the vortex ring in the oilpassage 21 located on the downstream side of the orifice 37 can besuppressed as compared with the orifice 31 of the above embodiments.

Here, the orifice 35, 36 or 37 shown in FIG. 5 could be combined withthe control valve body 1 having the protruding section 22, 25 or 26 ofthe above embodiments. Also with this combination, it is possible toprevent the vortex ring from being continuously formed in an orthogonaldirection of the orifice.

1. A structure of a control valve body of an automatic transmissioncomprising: valve body enclosures coupled together to form the controlvalve body, the valve body enclosures having channels on opposingsurfaces thereof; a separate plate sandwiched between the valve bodyenclosures, the separate plate defining oil passages on both sides ofthe separate plate by separating the channels between the valve bodyenclosures; and an orifice provided at the separate plate, the oilpassages on both sides of the separate plate, which are an upstream sideoil passage and a downstream side oil passage respectively located on anupstream side and a downstream side of the separate plate, communicatingwith each other through the orifice, and a depth h, at least in a partfacing to the orifice, of the channel corresponding to the downstreamside oil passage being set to be shallower than a depth of the channelcorresponding to the upstream side oil passage, and the death h of thechannel in the part facing to the orifice and a diameter d of theorifice being set so as to satisfy a relationship of h≦3d.
 2. Thestructure of the control valve body of the automatic transmission asclaimed in claim 1, wherein: the valve body enclosure in which thechannel having the depth h in the part facing to the orifice is formedis provided with a protruding section that faces to the separate platewhere the orifice is formed, and the protruding section has an opposingsurface that faces to the orifice.
 3. The structure of the control valvebody of the automatic transmission as claimed in claim 2, wherein: theopposing surface formed at the protruding section is a surface that isparallel to the separate plate where the orifice is formed.
 4. Thestructure of the control valve body of the automatic transmission asclaimed in claim 3, wherein: an area of the opposing surface is greaterthan an area of the orifice having the diameter d.
 5. The structure ofthe control valve body of the automatic transmission as claimed in claim1, wherein: the valve body enclosure in which the channel having thedepth h in the part facing to the orifice is formed is provided, in thepart facing to the orifice, with a circular truncated cone-shapedprotruding section.
 6. The structure of the control valve body of theautomatic transmission as claimed in claim 5, wherein: a top portionflat surface section of the protruding section is parallel to theseparate plate where the orifice is firmed, and an area of the topportion flat surface section of the protruding section is smaller thanan area of the orifice having the diameter d.
 7. The structure of thecontrol valve body of the automatic transmission as claimed in claim 2,wherein: the opposing surface formed at the protruding section is asurface that is not parallel to the separate plate where the orifice isformed.
 8. The structure of the control valve body of the automatictransmission as claimed in claim 7, wherein: an area of the opposingsurface is greater than an area of the orifice having the diameter d. 9.The structure of the control valve body of the automatic transmission asclaimed in claim 8, wherein: the opposing surface is formed as aninclined surface that descends from an upstream side toward a downstreamside of the downstream side oil passage while forming the channel havingthe depth h.
 10. The structure of the control valve body of theautomatic transmission as claimed in claim 1, wherein: the orifice is anorifice whose plane shape is noncircular and has a substantially innertooth shape.